CA1100756A - Process for the preparation of synthetic coking coal - Google Patents
Process for the preparation of synthetic coking coalInfo
- Publication number
- CA1100756A CA1100756A CA279,242A CA279242A CA1100756A CA 1100756 A CA1100756 A CA 1100756A CA 279242 A CA279242 A CA 279242A CA 1100756 A CA1100756 A CA 1100756A
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- Canada
- Prior art keywords
- coal
- coking
- coking coal
- src
- accord
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
- C10B57/00—Other carbonising or coking processes; Features of destructive distillation processes in general
- C10B57/04—Other carbonising or coking processes; Features of destructive distillation processes in general using charges of special composition
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
- Coke Industry (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Synthetic coking coal is prepared by mixing solvent refined coal with coal and heat-treating the resulting mixture at a temperature ranging from about 300°C to about 480°C, preferably from about 380°C to about 450°C.
Synthetic coking coal is prepared by mixing solvent refined coal with coal and heat-treating the resulting mixture at a temperature ranging from about 300°C to about 480°C, preferably from about 380°C to about 450°C.
Description
~ 10(J756 This invention relates to a process for the prepara-tion of synthetic coking coal using solvent refined coal.
As is well known, coking coal is essential to the production o~ coke for iron manufacture and the demand there-for is very high as iron production is increasing at the pre-sent time. However, the world-wide reserves of hard coking coal are very limited as compared with non-coking or soft coking coal reserves and they tend to be exhausted. Thus.
to deal with this problem, the utilization of non-coking coal, soft coking coal or other low coalified materials which are found in relatively abundant quantities is strongly desired, and many efforts for manufacturing synthetic coking coal from such low coalified materials have been made. This invention provides one method therefor.
As a reformed coal from low quality coals, solvent refined coal (SRC) is known, as disclosed, for example, in U. S. Patent No. 3,341,447 and in l'Research and Development Report No. 9, Solvent Processing of Coal to Produce a De-Ashed Product", the Department o~ the Interior, Office of Coal Research (presently the Energy Research and Development Administration~.
According to this patent and report, SRC is, in principle, a low ash-low sulfur product from solvent extrac-tion of coal under hydrogen pressure wherein coal is gener ally subjected to hydrocracking at a temperature of about 400C under a pressure of about 100 atm. in the presence or absence of a catalyst such as Co-Mo or Fe based catalyst, and the non-dissolved residue is removed from the hydro-cracked product (de-ashing step).
Practical application of SRC is now under study and industrial production thereof has not yet been begun.
However, in the light of its excellent quality, particularly .110()756 its low ash-low sulfur content, it is expected that SRC will, in the near future, obtain wide acclaim as a clean fuel.
ordinarily, SRC has the following general composi- -tion and properties:
Ultimate Analysis Items Percent by Weiqht Car~on (C) 85 - 94 Hydrogen (H) 4.0 - 6.5 Nitrogen (N) 0.5 - 20 Oxygen (O) 1.0 - 5.0 Sulfur (S) 0.1 - 1.0 O/C Atomic Ratio 0.015 - 0.040 Proximate Analysis Items Percent by Weiqht Fixed Carbon 41 - 45 Volatile matter 55 ~ 58 Ash content 0.1 - 0.5 Properties Softening point 85 - 150C
From the above, the features of SRC are summarized as follows:
(1) SRC has a high carbon content of about 85 - 94% by weight which lS comparable to that of coking coal, and its O/C atomic ratio is lower than 0.04.
As is well known, coking coal is essential to the production o~ coke for iron manufacture and the demand there-for is very high as iron production is increasing at the pre-sent time. However, the world-wide reserves of hard coking coal are very limited as compared with non-coking or soft coking coal reserves and they tend to be exhausted. Thus.
to deal with this problem, the utilization of non-coking coal, soft coking coal or other low coalified materials which are found in relatively abundant quantities is strongly desired, and many efforts for manufacturing synthetic coking coal from such low coalified materials have been made. This invention provides one method therefor.
As a reformed coal from low quality coals, solvent refined coal (SRC) is known, as disclosed, for example, in U. S. Patent No. 3,341,447 and in l'Research and Development Report No. 9, Solvent Processing of Coal to Produce a De-Ashed Product", the Department o~ the Interior, Office of Coal Research (presently the Energy Research and Development Administration~.
According to this patent and report, SRC is, in principle, a low ash-low sulfur product from solvent extrac-tion of coal under hydrogen pressure wherein coal is gener ally subjected to hydrocracking at a temperature of about 400C under a pressure of about 100 atm. in the presence or absence of a catalyst such as Co-Mo or Fe based catalyst, and the non-dissolved residue is removed from the hydro-cracked product (de-ashing step).
Practical application of SRC is now under study and industrial production thereof has not yet been begun.
However, in the light of its excellent quality, particularly .110()756 its low ash-low sulfur content, it is expected that SRC will, in the near future, obtain wide acclaim as a clean fuel.
ordinarily, SRC has the following general composi- -tion and properties:
Ultimate Analysis Items Percent by Weiqht Car~on (C) 85 - 94 Hydrogen (H) 4.0 - 6.5 Nitrogen (N) 0.5 - 20 Oxygen (O) 1.0 - 5.0 Sulfur (S) 0.1 - 1.0 O/C Atomic Ratio 0.015 - 0.040 Proximate Analysis Items Percent by Weiqht Fixed Carbon 41 - 45 Volatile matter 55 ~ 58 Ash content 0.1 - 0.5 Properties Softening point 85 - 150C
From the above, the features of SRC are summarized as follows:
(1) SRC has a high carbon content of about 85 - 94% by weight which lS comparable to that of coking coal, and its O/C atomic ratio is lower than 0.04.
(2) SRC has higher hydrogen content, higher volatile matter and lower oxygen content than ordinary coal.
(3) SRC has a softening point of about 100C or so.
(4) From any types of starting coal material (for example.
even from low quality material such as brown coal), SRC pro-ducts of closely resembling composition or properties can be obtained. (This is more specifically described hereinafter with respect to Table I).
1101~756 E'rom the above analysis, it can be seen that SRC
is most considerably different from natural hard coking coal in the point that the former has higher volatile matter and lower softening point, as compared with the latter. Some examples of ordinary starting coals for the production of metallurgical coke are shown as follows:
Initial Volatile Melting Brand matter(wt.%) CS~I Point(C) Itmann(U,S.A.) 16 - 19 7-9 ~27 Wyco ( " ) 16 - 18 8-9 403 Moss No.3 ~ ~ ) 26 - 28 8-9 355 South sulli 21 - 23 5--6 410 (Australia) Liddell ( " ) 37 - 39 5-6 385 Akabira (Japan) 40 - 42 4-5 334 Thus, it is difficult to use SRC itself in the production of coke for iron manufacturi~g, but if its vola-tile matter i-s lowered and its softening point is raised by means of any suitakle technique, it may be expected that a good coking material having quality equivalent to that of natural coking coal can be obtained. This invention is based on such consideration.
It has now been found that good coking carbonaceous material having a quality equivalent to that of natural coking coal can be produced by mixing solvent refined coal with coal and heat-treating the mixture at a temperature of from about 300C to about 480C preferably from about 380C to about 450C. According to the present invention, synthetic high quality coking coal can be easily produced from low priced and abundant low-coalified materials.
According to the present invention, there is pro-vided a process for the preparation of synthetic coking coal ~1~)()756 which comprises mixiny solvent refined coal with coal and heat-treating the resulting mixture at a temperature of akout 300C -480C, preferably about 380C - 450C.
The solvent re~ined coal, i.e. SRC used in the present invention is any material having a general composition and pro-perties as mentioned hereinbefore, known per se. In addition, it is not always necessary for SRC to be de-ashec, for the pur-pose of the present invention, while so-called SRC is a de-ashed product from coal.
This is because cokes which are currently used for iron-manufacturing have ash content of about 10% by weight or more, and thus SRC containing ash to some extent can also give a desired coke without any trouble.
In the present invention, "coals" to be added to SRC
(hereinafter, referred to "additive coal") include non-coking coals such as li~nite, brown coal, sub-bituminous coal and anthracite, and coking coals such as weak-coking coal, soft coking coal, and hard coking coal. Preferred additive coals are weak and soft coking coal.
Said SRC and additive coals are preferably used in a granular or powdery form, and the particle size thereof is generally less than about 1 mm, pre~erably less than 28 mesh.
In the present invention, the SRC and the additive ; coal are mixed in a proportion of about 1 : 0.25-4, preferably about 1 : 0.5-2 (as weight ratio), The heat-treatment according to the present invention is generally effected at a temperature within the range of about 300C to about 480C, preferably about 380C - 450C
Temperatures of this range are generally between the softening or initial melting temperature and solidification temperature of the preferred additive coal i.e. coking coal. Thus, when a coking coal such as weak coking or soft coking coal is used as 110(~7S6 the additive coal ~he heat-treatrnerlt of the SRC-additive coal mixture is performed in a state wherein the SRC and additive coal are both melted.
~Iowever, according to the present invention, when non-coking coal such as brown coal which is not thermally melted is used as the additive coal, the desired good coking material can also be obtained by heat-treatment in the above temperature range, particularly the preferred temperature range.
We cannot theoretically explain the reason why the desired effect is achieved by the heat-treatment o~ the mixture of SRC and additive coal at said specific temperature range.
The present invention is based merely on the fact that the actual desired efect can be obtained by mixing SRC with addi-tive coal and heat-txeating the mixture at a temperature between about 300C - 480C, preferably about 380C - 450C.
The heat-treating time is generally about 1/2 - 7 hours, preferably 1 - 2 hours. Also, the heat-treatment accord-ing to the present invention may be effected under atmospheric pressure or pressure of up to about 10 atm.
According to the present invention which is carried out as mentioned above, good quality coking carbonaceous pro-ducts having volatile matter contents of about 15 - 3S% prefer-ably 18 - 30% and softening point of more than about 300C can be formed from SRC and ordinary coal stock. These products are fully comparable to natural coking coal which is usually employed as a starting material for the production of coke for iron manufacturingO
Particularly, the essential advantage of the present invention is that good quality synthetic coking material can be obtained even from low quality additive coals, e.g., non-coking coal such as brown coal or sub-bituminous coal, and weak or soft coking coal. This fact and the fact that SRC itself ~L10(~7S6 starts ~rom low quality coal constltute a great economical advantage in the art. Of course, the use of good quality coal such as coking coal as the additive coal is also effective but the economical merit thereof is not so high. However, we be-lieve that in the present invention, the additive coal itself is also reformed by SRC. Thus, it will be expected that coals with low fluidity suc~ as Canadian or Australian hard coking coal can be reformed in their fluidity according to the pro-cess of the present invention.
The synthetic coking coal prepared according to the process of the present invention may be employed for the pro-duction of metallurgical coke, as it is. Preferably, it is mixed together with ordinary natural coking coal to produce coke for iron manufacturing.
The type of coking coal to be mixed and the added amount thereof depend on the properties of the synthetic coking coal according to the present invention. In turn, a synthetic coking coal having properties compatible with a natural coking coal to be mixed may be produced according to the present in-vention.
In summary, according to the present invention, good quality metallurgical coke can be easily and economically pre-pared from any type of coals, by properly selecting (1) the properties of SRC, (2) the type and amount of additive coal, (3) the conditions of heat-treatment and (4) the type of natural coking coal used in the production o coke (i necessary), The present invention is now described in detail by way o some preferred examples. Unless otherwise speciied, all percentages and parts are by weight in the examples.
As described hereinbefore, the SRC to be used in the present invention is now under study. Thus, since it was com-mercially unavailable, we obtained three trial manufactured SRC
~\
0()756 samples which were laboratorily prepared according to the proce-dure as mentioned hereinbefore and used them in the examples.
These three SRC samples are shown in Table I below:
" 1101)756 f--~
~ , ~ o .,, _ o o o a~ ~ ~ o , rl o o ~rl ~ O ~ ~ ~
3 X R d~ ~ o ~ ta ~ ~
~ C) . .
lq ~_ a) ~ o ~ o a) .,_1 .,~ ~ ~ ~ . .
~Ul ~ ~ ~
~~ ~1 1~ ~ ~O h~ ~
~r-l ~0 ~ ~ .
H ~ :1 ~1 I
~X ~ ~ O O U) P~ ~1~O~ V~:
. U~
~ . ~.
.~ ,1 ol a~ O ~
~1 ~ C~ o ~ o o o H O O C~
I ~,) a) P~
R u~ ~ 0 ~ :
~ ~ ~u~ ~ 0 o E~ O ~ v~. . . U
o o o ,1 ~ ~ ~ a .~ 3 ~0 R
o ~ ~ o a _ rl r~ -u~ o ~ n a) ,~ ~
~:: ~ ~ h ~1 I
~s ~
~) n~
e c~ 0 ~ ~ Ro ~ I 0 o ~
~ m c~
mc~
U~ :
.
~. .
110(~756 From the above, it is noted that the compositions and properties of said three SRC samples closely resemble each other regardless of the type of starting coal used. This is very ad-vantageous for the purpose of the present invention to obtain high quality coking material from low coalified material.
Example 1 Said A, B and C SRC samples and two types of additive coals were used to from six SRC-additive coal mixtures. The two additive coals used were weak coking coal D and soft coking 0 coal E, as shown in Table II below:
Table II
Properties of Additive Coal used in Mixinq with SRC
Fixed Initial Moisture Ash Volatile Carbon Melting (%) (%) matter(%)(%) CSN Point(C) D coal 3.1 8.0 36.0 52.g 2 380 E coal 1.1 6.9 40.5 51.5 3 1/2 363 The SRC and the additive coal were pulverized into less than 60 mesh, and then homogeneously mixed in a proportion of 0.5 parts of additlve coal per one part of SRC. The so-obtained mixture was placed in a retort with side arm, providedwith a stirrer, and then heat-treated at 400C for 60 minutes therein. During the heat-treatment, gases and low boiling point materials were produced and effused from the retort. The heat-treated material which remained as residue in the retort was recovered as the synthetic coking coal.
The properties of the so-obtained six synthetic coking coals were examined according to the determining procedure des-cribed in JIS M-8801. The results are shown in Table III below.
In the table, A', B' and C' are synthetic coking coals which were obtained from SRC A, B and C mixed with additive coal D, respectively, and A", B" and C" are ones which were obtained from A, B and C SRC mixed with additive coal E, respectively.
11()()756 Table III
Properties and Yield of Syn-thetic Cokinq Coal Fixed Volatile Initial Yield Carbon matter Ash Melting (%) (%) (%) (%) CS~ Point(Cj A~ 75 74 22 4 9 310 Bl 77 70 26 4 9 315 C~ 77 69 23 8 9 320 A" 79 74 23 3 9 300 C" 77 68.5 24 7.5 9 315 As seen from Table III, the product prepared accord-ing to the present invention has much lowered volatile matter and highly enhanced softening point, as compared with the starting SRC. Further, it has CSN (Crucible Swelling Number) of 9 as high.
Cokes were then prepared using the above prepared synthetic coking coals.
Akabira coal having 41% of volatile matter, 50.5% of fixed carbon and 6.6% of ash (soft coking coal produced in Hokkaido, Japan) was employed as base coal, and this base coal was mixed with 30% by weight of the above prepared synthetic coking coals Al, B~, C~, A", Bl' and C" to form six coal mix-tures. Each mixture was then coked by means of a conventional coking process. Each of the so-obtained coked products had more than 90 of coke strength (DI3150). For the purpose of comparison, another coke product was prepared according to the procedure as described above, excepting that Itmann hard coking coal having , 18% of volatile matter, 75% of fixed carbon and 6% of ash (pro-duced in Virginia, U.S.A.) was substituted for the synthetic coking coal. The obtained coke has more than 90 of strength (DI150). Further, straight cokes from synthetic coking coal A~, said Akabira coal and said Itmann coal employed had 93, 65 and 93 110(17s~
o~ coke strength (DI15), respectively.
From the above, it is easily seen that the synthetic coking coal prepared according to the present process can be used alone or in combination with other natural coking coal to give a good quality metallurgical co}ce product. Particu-larly, it is surprising that the synthetic coking coal prepared according to the present process giYes good quality coke com-parable to that from the Itmann coal which is a good qualtiy natural coking coal.
In Example 1, the prepara~ion o synthetic coking coal using, as the additive coal, a weak coking coal and a soft coking coal which are lower rank bituminous coals was shown.
According to the present invention, it is also pos-sible to produce good quality coking coal from other low qua-lity aaditive coals such as non-coking coal.
The following example shows the use of non-coking coal as the additive coal.
Example 2 The SRC samples A and C and Taiheiyo coal (non-coking coal produced in Hokkaido, Japan) were used to form synthetic coking coals.
Said Taiheiyo coal had the following properties:
Moisture 7.0%
Ash 7.1%
Volatile matter 41.1%
~ixed carbon 45.5%
The SRC was pulverized into less than 60 mesh, and the additive coal was pulverized into less than 100 mesh~
After the so-pulverized SRC and additive coal were dried, they were homogeneously mixed in a proportion of 0.25 parts of addi-tive coal per one part of SRC, and the resulting mixture was ~O~J7S6 then placecl i~ etort with side arm, provided with a stirrer and subjected to heat-treatment at 420C for one hour. During the treatment, gases and low boiling point material were pro-duced and effused out from the retort. The heat-treated product which remained as residue in the retort was recovered as syn-thetic coking coal.
The properties of the so-obtained two synthetic coking coals were examined according to the procedure described in JIS M-8801. The results are shown in the following Table IV:
Table IV
Products A (a) C~ (b) Yield (%) 72 74 Fixed Carbon (%) 73 65 Volatile Matter (%) 23.7 25.3 Ash (%) 3 3 9 7 Initial Melting Point (C) 315 320 (a) : Obtained using SRC sample A.
~b) : Obtained using SRC sample C.
The above Table IV clearly shows that, when non-coking coal which is not thermally melted is used as the additive coal, according to the present invention, there can also be obtained a good coking product having excellent coking properties equi-valent or superior to those of natural coking coal.
Then, the above prepared synthetic coking coals A"l and C"'and Taiheiyo coal as base coal ~ùsed in Example 1) were used to form cokes according to the procedure as described in Example 1. The two cokes obtained had more than 90 of strength (DI15)' ., : , '
even from low quality material such as brown coal), SRC pro-ducts of closely resembling composition or properties can be obtained. (This is more specifically described hereinafter with respect to Table I).
1101~756 E'rom the above analysis, it can be seen that SRC
is most considerably different from natural hard coking coal in the point that the former has higher volatile matter and lower softening point, as compared with the latter. Some examples of ordinary starting coals for the production of metallurgical coke are shown as follows:
Initial Volatile Melting Brand matter(wt.%) CS~I Point(C) Itmann(U,S.A.) 16 - 19 7-9 ~27 Wyco ( " ) 16 - 18 8-9 403 Moss No.3 ~ ~ ) 26 - 28 8-9 355 South sulli 21 - 23 5--6 410 (Australia) Liddell ( " ) 37 - 39 5-6 385 Akabira (Japan) 40 - 42 4-5 334 Thus, it is difficult to use SRC itself in the production of coke for iron manufacturi~g, but if its vola-tile matter i-s lowered and its softening point is raised by means of any suitakle technique, it may be expected that a good coking material having quality equivalent to that of natural coking coal can be obtained. This invention is based on such consideration.
It has now been found that good coking carbonaceous material having a quality equivalent to that of natural coking coal can be produced by mixing solvent refined coal with coal and heat-treating the mixture at a temperature of from about 300C to about 480C preferably from about 380C to about 450C. According to the present invention, synthetic high quality coking coal can be easily produced from low priced and abundant low-coalified materials.
According to the present invention, there is pro-vided a process for the preparation of synthetic coking coal ~1~)()756 which comprises mixiny solvent refined coal with coal and heat-treating the resulting mixture at a temperature of akout 300C -480C, preferably about 380C - 450C.
The solvent re~ined coal, i.e. SRC used in the present invention is any material having a general composition and pro-perties as mentioned hereinbefore, known per se. In addition, it is not always necessary for SRC to be de-ashec, for the pur-pose of the present invention, while so-called SRC is a de-ashed product from coal.
This is because cokes which are currently used for iron-manufacturing have ash content of about 10% by weight or more, and thus SRC containing ash to some extent can also give a desired coke without any trouble.
In the present invention, "coals" to be added to SRC
(hereinafter, referred to "additive coal") include non-coking coals such as li~nite, brown coal, sub-bituminous coal and anthracite, and coking coals such as weak-coking coal, soft coking coal, and hard coking coal. Preferred additive coals are weak and soft coking coal.
Said SRC and additive coals are preferably used in a granular or powdery form, and the particle size thereof is generally less than about 1 mm, pre~erably less than 28 mesh.
In the present invention, the SRC and the additive ; coal are mixed in a proportion of about 1 : 0.25-4, preferably about 1 : 0.5-2 (as weight ratio), The heat-treatment according to the present invention is generally effected at a temperature within the range of about 300C to about 480C, preferably about 380C - 450C
Temperatures of this range are generally between the softening or initial melting temperature and solidification temperature of the preferred additive coal i.e. coking coal. Thus, when a coking coal such as weak coking or soft coking coal is used as 110(~7S6 the additive coal ~he heat-treatrnerlt of the SRC-additive coal mixture is performed in a state wherein the SRC and additive coal are both melted.
~Iowever, according to the present invention, when non-coking coal such as brown coal which is not thermally melted is used as the additive coal, the desired good coking material can also be obtained by heat-treatment in the above temperature range, particularly the preferred temperature range.
We cannot theoretically explain the reason why the desired effect is achieved by the heat-treatment o~ the mixture of SRC and additive coal at said specific temperature range.
The present invention is based merely on the fact that the actual desired efect can be obtained by mixing SRC with addi-tive coal and heat-txeating the mixture at a temperature between about 300C - 480C, preferably about 380C - 450C.
The heat-treating time is generally about 1/2 - 7 hours, preferably 1 - 2 hours. Also, the heat-treatment accord-ing to the present invention may be effected under atmospheric pressure or pressure of up to about 10 atm.
According to the present invention which is carried out as mentioned above, good quality coking carbonaceous pro-ducts having volatile matter contents of about 15 - 3S% prefer-ably 18 - 30% and softening point of more than about 300C can be formed from SRC and ordinary coal stock. These products are fully comparable to natural coking coal which is usually employed as a starting material for the production of coke for iron manufacturingO
Particularly, the essential advantage of the present invention is that good quality synthetic coking material can be obtained even from low quality additive coals, e.g., non-coking coal such as brown coal or sub-bituminous coal, and weak or soft coking coal. This fact and the fact that SRC itself ~L10(~7S6 starts ~rom low quality coal constltute a great economical advantage in the art. Of course, the use of good quality coal such as coking coal as the additive coal is also effective but the economical merit thereof is not so high. However, we be-lieve that in the present invention, the additive coal itself is also reformed by SRC. Thus, it will be expected that coals with low fluidity suc~ as Canadian or Australian hard coking coal can be reformed in their fluidity according to the pro-cess of the present invention.
The synthetic coking coal prepared according to the process of the present invention may be employed for the pro-duction of metallurgical coke, as it is. Preferably, it is mixed together with ordinary natural coking coal to produce coke for iron manufacturing.
The type of coking coal to be mixed and the added amount thereof depend on the properties of the synthetic coking coal according to the present invention. In turn, a synthetic coking coal having properties compatible with a natural coking coal to be mixed may be produced according to the present in-vention.
In summary, according to the present invention, good quality metallurgical coke can be easily and economically pre-pared from any type of coals, by properly selecting (1) the properties of SRC, (2) the type and amount of additive coal, (3) the conditions of heat-treatment and (4) the type of natural coking coal used in the production o coke (i necessary), The present invention is now described in detail by way o some preferred examples. Unless otherwise speciied, all percentages and parts are by weight in the examples.
As described hereinbefore, the SRC to be used in the present invention is now under study. Thus, since it was com-mercially unavailable, we obtained three trial manufactured SRC
~\
0()756 samples which were laboratorily prepared according to the proce-dure as mentioned hereinbefore and used them in the examples.
These three SRC samples are shown in Table I below:
" 1101)756 f--~
~ , ~ o .,, _ o o o a~ ~ ~ o , rl o o ~rl ~ O ~ ~ ~
3 X R d~ ~ o ~ ta ~ ~
~ C) . .
lq ~_ a) ~ o ~ o a) .,_1 .,~ ~ ~ ~ . .
~Ul ~ ~ ~
~~ ~1 1~ ~ ~O h~ ~
~r-l ~0 ~ ~ .
H ~ :1 ~1 I
~X ~ ~ O O U) P~ ~1~O~ V~:
. U~
~ . ~.
.~ ,1 ol a~ O ~
~1 ~ C~ o ~ o o o H O O C~
I ~,) a) P~
R u~ ~ 0 ~ :
~ ~ ~u~ ~ 0 o E~ O ~ v~. . . U
o o o ,1 ~ ~ ~ a .~ 3 ~0 R
o ~ ~ o a _ rl r~ -u~ o ~ n a) ,~ ~
~:: ~ ~ h ~1 I
~s ~
~) n~
e c~ 0 ~ ~ Ro ~ I 0 o ~
~ m c~
mc~
U~ :
.
~. .
110(~756 From the above, it is noted that the compositions and properties of said three SRC samples closely resemble each other regardless of the type of starting coal used. This is very ad-vantageous for the purpose of the present invention to obtain high quality coking material from low coalified material.
Example 1 Said A, B and C SRC samples and two types of additive coals were used to from six SRC-additive coal mixtures. The two additive coals used were weak coking coal D and soft coking 0 coal E, as shown in Table II below:
Table II
Properties of Additive Coal used in Mixinq with SRC
Fixed Initial Moisture Ash Volatile Carbon Melting (%) (%) matter(%)(%) CSN Point(C) D coal 3.1 8.0 36.0 52.g 2 380 E coal 1.1 6.9 40.5 51.5 3 1/2 363 The SRC and the additive coal were pulverized into less than 60 mesh, and then homogeneously mixed in a proportion of 0.5 parts of additlve coal per one part of SRC. The so-obtained mixture was placed in a retort with side arm, providedwith a stirrer, and then heat-treated at 400C for 60 minutes therein. During the heat-treatment, gases and low boiling point materials were produced and effused from the retort. The heat-treated material which remained as residue in the retort was recovered as the synthetic coking coal.
The properties of the so-obtained six synthetic coking coals were examined according to the determining procedure des-cribed in JIS M-8801. The results are shown in Table III below.
In the table, A', B' and C' are synthetic coking coals which were obtained from SRC A, B and C mixed with additive coal D, respectively, and A", B" and C" are ones which were obtained from A, B and C SRC mixed with additive coal E, respectively.
11()()756 Table III
Properties and Yield of Syn-thetic Cokinq Coal Fixed Volatile Initial Yield Carbon matter Ash Melting (%) (%) (%) (%) CS~ Point(Cj A~ 75 74 22 4 9 310 Bl 77 70 26 4 9 315 C~ 77 69 23 8 9 320 A" 79 74 23 3 9 300 C" 77 68.5 24 7.5 9 315 As seen from Table III, the product prepared accord-ing to the present invention has much lowered volatile matter and highly enhanced softening point, as compared with the starting SRC. Further, it has CSN (Crucible Swelling Number) of 9 as high.
Cokes were then prepared using the above prepared synthetic coking coals.
Akabira coal having 41% of volatile matter, 50.5% of fixed carbon and 6.6% of ash (soft coking coal produced in Hokkaido, Japan) was employed as base coal, and this base coal was mixed with 30% by weight of the above prepared synthetic coking coals Al, B~, C~, A", Bl' and C" to form six coal mix-tures. Each mixture was then coked by means of a conventional coking process. Each of the so-obtained coked products had more than 90 of coke strength (DI3150). For the purpose of comparison, another coke product was prepared according to the procedure as described above, excepting that Itmann hard coking coal having , 18% of volatile matter, 75% of fixed carbon and 6% of ash (pro-duced in Virginia, U.S.A.) was substituted for the synthetic coking coal. The obtained coke has more than 90 of strength (DI150). Further, straight cokes from synthetic coking coal A~, said Akabira coal and said Itmann coal employed had 93, 65 and 93 110(17s~
o~ coke strength (DI15), respectively.
From the above, it is easily seen that the synthetic coking coal prepared according to the present process can be used alone or in combination with other natural coking coal to give a good quality metallurgical co}ce product. Particu-larly, it is surprising that the synthetic coking coal prepared according to the present process giYes good quality coke com-parable to that from the Itmann coal which is a good qualtiy natural coking coal.
In Example 1, the prepara~ion o synthetic coking coal using, as the additive coal, a weak coking coal and a soft coking coal which are lower rank bituminous coals was shown.
According to the present invention, it is also pos-sible to produce good quality coking coal from other low qua-lity aaditive coals such as non-coking coal.
The following example shows the use of non-coking coal as the additive coal.
Example 2 The SRC samples A and C and Taiheiyo coal (non-coking coal produced in Hokkaido, Japan) were used to form synthetic coking coals.
Said Taiheiyo coal had the following properties:
Moisture 7.0%
Ash 7.1%
Volatile matter 41.1%
~ixed carbon 45.5%
The SRC was pulverized into less than 60 mesh, and the additive coal was pulverized into less than 100 mesh~
After the so-pulverized SRC and additive coal were dried, they were homogeneously mixed in a proportion of 0.25 parts of addi-tive coal per one part of SRC, and the resulting mixture was ~O~J7S6 then placecl i~ etort with side arm, provided with a stirrer and subjected to heat-treatment at 420C for one hour. During the treatment, gases and low boiling point material were pro-duced and effused out from the retort. The heat-treated product which remained as residue in the retort was recovered as syn-thetic coking coal.
The properties of the so-obtained two synthetic coking coals were examined according to the procedure described in JIS M-8801. The results are shown in the following Table IV:
Table IV
Products A (a) C~ (b) Yield (%) 72 74 Fixed Carbon (%) 73 65 Volatile Matter (%) 23.7 25.3 Ash (%) 3 3 9 7 Initial Melting Point (C) 315 320 (a) : Obtained using SRC sample A.
~b) : Obtained using SRC sample C.
The above Table IV clearly shows that, when non-coking coal which is not thermally melted is used as the additive coal, according to the present invention, there can also be obtained a good coking product having excellent coking properties equi-valent or superior to those of natural coking coal.
Then, the above prepared synthetic coking coals A"l and C"'and Taiheiyo coal as base coal ~ùsed in Example 1) were used to form cokes according to the procedure as described in Example 1. The two cokes obtained had more than 90 of strength (DI15)' ., : , '
Claims (10)
1. A process for preparing synthetic coking coal which comprises mixing solvent refined coal with at least one coal and heat-treating the mixture at a temperature within a range of from about 300°C to about 480°C.
2. A process for preparing synthetic coking coal accord-ing to claim 1 wherein the heat-treating temperature ranges from about 380°C to about 450°C.
3. A process for preparing synthetic coking coal accord-ing to claim 1 wherein the solvent refined coal and coal are mixed in a proportion of about 1 : 0.25-4, by weight.
4. A process for preparing synthetic coking coal accord-ing to claim 3 wherein the solvent refined coal and coal are mixed in a proportion of about 1 : 0.5-2, by weight.
5. A process for preparing synthetic coking coal accord-ing to claim 1 wherein the heat-treatment is carried out for a time period of about 1/2 to about 7 hours.
6. A process for preparing synthetic coking coal accord-ing to claim 5 wherein the heat-treating time is about 1 to about 2 hours.
7. A process for preparing synthetic coking coal accord-ing to claim 1 wherein the coal to be mixed with solvent refined coal is coking coal.
8. A process for preparing synthetic coking coal accord-ing to claim 7 wherein the coking coal is selected from the group consisting of weak coking coal and soft coking coal.
9. A process for preparing synthetic coking coal accord-ing to claim 1 wherein the coal to be mixed with solvent refined coal is non-coking coal.
10. A process for preparing synthetic coking coal accord-ing to claim 9 wherein the non-coking coal is selected from the group consisting of lignite, brown coal, sub-bituminous coal and anthracite.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP51060563A JPS5845995B2 (en) | 1976-05-27 | 1976-05-27 | Manufacturing method of artificial caking coal |
| JP60563/1976 | 1976-05-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1100756A true CA1100756A (en) | 1981-05-12 |
Family
ID=13145850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA279,242A Expired CA1100756A (en) | 1976-05-27 | 1977-05-26 | Process for the preparation of synthetic coking coal |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4119409A (en) |
| JP (1) | JPS5845995B2 (en) |
| AU (1) | AU501635B2 (en) |
| CA (1) | CA1100756A (en) |
| ZA (1) | ZA773173B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4252539A (en) * | 1979-07-12 | 1981-02-24 | Texaco Inc. | Solid fuel composition |
| JPS58187490A (en) * | 1982-04-28 | 1983-11-01 | Mitsui Sekitan Ekika Kk | Preparation of coke having high strength and low ash content |
| US4605421A (en) * | 1984-09-10 | 1986-08-12 | Kerr-Mcgee Chemical Corporation | Process for the preparation of a carbonaceous-derived solid fuel product |
| JP4395639B2 (en) | 2005-03-29 | 2010-01-13 | アイマー・プランニング株式会社 | Printer |
| JP3899426B2 (en) | 2005-03-29 | 2007-03-28 | アイマー・プランニング株式会社 | Printer |
| JP5394695B2 (en) * | 2007-10-31 | 2014-01-22 | 竹司 目黒 | Method for reforming non-caking coal with low coalification degree, molding for modifying non-caking coal, and method for producing coke |
| JP5679335B2 (en) * | 2011-10-13 | 2015-03-04 | 株式会社神戸製鋼所 | Coal mixed fuel and combustion method thereof |
| US9567654B2 (en) | 2014-06-24 | 2017-02-14 | Uop Llc | Binder for metallurgical coke and a process for making same |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3341447A (en) * | 1965-01-18 | 1967-09-12 | Willard C Bull | Solvation process for carbonaceous fuels |
| US3933443A (en) * | 1971-05-18 | 1976-01-20 | Hugo Lohrmann | Coking component |
| US3980447A (en) * | 1972-04-26 | 1976-09-14 | Rheinische Braunkohlenwerke Ag | Process for the manufacture of brown coal briquettes |
-
1976
- 1976-05-27 JP JP51060563A patent/JPS5845995B2/en not_active Expired
-
1977
- 1977-05-20 AU AU25347/77A patent/AU501635B2/en not_active Expired
- 1977-05-23 US US05/799,165 patent/US4119409A/en not_active Expired - Lifetime
- 1977-05-26 ZA ZA00773173A patent/ZA773173B/en unknown
- 1977-05-26 CA CA279,242A patent/CA1100756A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4119409A (en) | 1978-10-10 |
| JPS5845995B2 (en) | 1983-10-13 |
| AU2534777A (en) | 1978-11-23 |
| JPS52144002A (en) | 1977-12-01 |
| AU501635B2 (en) | 1979-06-28 |
| ZA773173B (en) | 1978-05-30 |
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